Automatic night light



- Sept-2, 1958 w. A. SMITH 2,350,675

AUTOMATIC NIGHT LIGHT Filed Aug. 30, 1955 mm a a i 5 mm mm m om w a WAYNE A. SMITH IN V EN TOR.

ATTORNEY 7 2,850,675 Patented Sept. 2, 1958 Wayne A. Smith, Fort Worth, Application August 3%, 1955, Serial No. 531,347

4 Claims. (i. 315- 93) This invention relates to lighting systems wherein continuous operation is maintained in the event of failure of a main bulb or electrical unit or when the main power supply is interrupted.

Night lights are widely used in commercial establishments to discourage theft and to display merchandise through the night. Failure of a night light may enable burglars to enter an establishment unobserved. Aside from the fact that light bulbs have a limited life, power failures due to blown fuses or transmission difiiculties result in periods when normal means of illumination are not available and theft is thereby encouraged. In addition to normal commercial applications there are a number of uses where continuous operation of light bulbs or other appliancesis of great importance; among these special uses for continuous operation are airport runway illuminators, electric lights used for heating purposes in brooder houses and operation of electrical i An object of the invention is to provide an electrical circuit for illuminating devices wherein a reserve bulb is automatically turned on in the event that a regularly used bulb should fail.

Another object of the invention is to provide an illuminating device which automatically substitutes battery operated illuminating means when power failures eliminate a normal source of line current.

Another object of the invention is to provide a reliable means of illumination which may be actuated by either manual or clock controlled means.

Another object of the invention is to provide means wherein the clock controlled operation of a reliable illuminating device may be utilized to connect and disconnect less important circuits, such as lighted circuits with line current.

Another object of the invention is to provide an arrangement of components in a reliable illuminating source wherein widely separated bulbs, each provided with automatic substitution means, may be actuated from one clock controlled source.

I A further object of the invention is to provide separate and independently operable batteries for each of a number of emergency sources or" illumination wherein battery operation is supplied to each source as needed and yet all sources are controlled by the clock operation of a master unit.

These and other objects will become apparent rom the following description and the accompanying drawing, wherein:

Figure l is a diagrammatic view of a master unit of the invention.

Figure 2 is a diagrammatic view of a subordinate unit of the invention.

In the drawing, one wire 11 of a current source is electrically connected to one armature 12 of a double pole double throw switch A. The upper or first contact point 13 of the armature lZis wired electrically to one contact point 14 of a double pole single throw clock operated switch 15. Any of a number of commercially iii available mechanical or electrical clock operated switches may be used, and if electrical, should be wired in parallel with power supply as indicated by the dotted lines 16 and 17 and with the circuits to be described. The armature 18 opposite the contact point 14 of the clock oper ated switch is wired through a fuse 19 to one binding post of the actuating coil of a normally closed single pole single throw relay 20. One binding post of the actuating coil of a double pole double throw relay 21 is likewise wired through the fuse 19 to the same armature 18 of the clock operated switch 15. The other binding post of the actuating coil of the double pole double throw relay 21 is wired to one terminal of an electric light bulb 22; the same terminal of the electric light bulb 22 is wired to the armature 18 of the clock operated switch 15 through a resistor 23 and the fuse 19 successively. An'other resistor 24 is wired in parallel with the first mentioned resistor 23 and in series with the light bulb Z2 and is provided with a switch 25 at one of its terminals in series with the resistor 24. The other terminal of the light bulb 22 is wired through a switch 26 to the second wire 27 of the current source. The other binding post of the actuating coil of the single pole single throw relay l is wired to one armature 28, hereinafter referred to as the first armature, of the double pole double throw relay 2%. The normally open contact point 29 of the first armature 28 of the double pole double throw relay 21 is wired to the first mentioned terminal of the electric light bulb 22. The normally closed contact point 30 of the first armature 2d of the double pole double throw relay 21 is wired to one terminal of a second light bulb 31. The same terminal of the second light :bulb 31 is wired to the armature 18 of the clock operated switch 15 through a resistor 32 and the fuse l9 successively. Another resistor 33 is wired in parallel with the resistor 32 and in series with the light bulb 31 and is provided with a switch 34 at one of its terminals-in series with the resistor 33. The other terminal of the second light bulb 31 is electrically connected to the normally closed contact point 35 of the second armature 35 of the double pole double throw relay 21. The second armature 36 of the double pole double throw relay 21 is wired through a switch 37 to the second wire 27 of the current source.

A battery 38 is wired from one of its terminals to the armature 39 of the single pole single throw relay 20. The normally closed contact point 40 of the single pole single throw relay is electrically connected to one terminal of a third electric light bulb 41. The other terminal of the third light bulb 41 is wired tothe lower or second contact point 42 of the second armature 43 of the double pole double throw switch A. The second contact point 42 of the second armature 43 of the double pole double throw switch A is also wired to the contact point 44 of the second armature 45 of the clock operated switch 15. The second armature :5 of the clock operated switch 15 is wired to the upper or first contact point 46 of the second armature 43 of the double pole double throw switch A. The second armature 43 of the double pole double throw switch A is wired to the second terminal of the battery 38. The second or lower contact point 47 of the first armature 3.2 of the double pole double throw switch A is wired to the fuse 19. A push button switch 48 is connected between the second armature 43 of the double pole double throw switch A and the second contact point 42 of the armature 43.

Line current outlet lines and are electrically connected respectively second wire 27 of the current source and through a fuse to the second contact point 47 of the first armamre 32 of the double pole double throw switch A. Control current outlet lines 52 and 53 connected respectively to the first terminal of the oat- 'third light- 41:

tery 38 and to the second contact point 42 of the second armature 43 of the double pole double throw switch A.

In operation of the master;unit described, the circuit of theactuating coil oi-thedoublepoledouble throw relay 2 V is connected; to thefirst; wire lief the linecurrent through the clock operated, switch 1l5.and.,the doublerpole. double throw vswitch A; and. tliat circuit .is. completed tothe second-wire 27 of the line current sourcethroughtthe filamentof; the first light bulb 2 2. 'As long as theLfiIament,

of the first-light bulb 22. is intact, currenttfio-ws through the actuating coil of thedouble pole double relay 21 did the arrnatures thereof 28; and-36. are. held against their normally cpen contact points; In their. described actu-.

atediipositions, one ofithese; arrnatures.36 =interrupts the circuit pf-the- 'secondlight bulbfSl whilethe. other metasshunts line; currentfromathe coil circuit of the single pole singlethrolw relay 20;.through the filament of thetfirstrbulbqfl thereby energizing-the single pole single throw; relay: 26,. andgactuating its armature 3). V armature 39;;of1the'single pole singlethrow relay-24i in The through a clock operated switch, or to turn the invention for testing the strength of the battery and the workingorder of the battery'operated light 41.

A line current outlet 49 and 5t subject to the operations 'of the clock operated switch and the double pole double throw switch A, is provided for thet0peration of external lights and appliances electrically con terruptsthecircnit; of: the battery operatedathirdslight bulb; 41r when: actuated. I So' long as the filamentiofthe first hulb:22 ;iis;.capable of conductinggcurrent and soilcmg astlille currentis, available therefor, the circuits of the other two. bulbs: 31. and'41. are interrupted lay-actuation oft-the relays Zkandlfizand only thefirst bulb ZZrecerves currentxfor illumination. 'The first bulb 22;is connected with current'frornuthezfirst wire 11 of the line current source. through ;a.resistor, 23,. the resistance of WlllChiS properly.calibnatedzto provide suitable division or" current between the coils of the relays Zilyand 2,1 and the; first light bulb. 22. Anadditional resistor 2.4 is wired in parallel with the first resistor 23 and is provided with 'a' switch 25 by which it may be utilized optionally to maintain-suitable current .balance with the coils of the relays 20tand- 21 if the uselof'a higher wattage bulbgis desired."

It iwill be apparent to those skilled in the art that addi-' tional resistors or a rheostat may be'employed to ace-en modatea large variety of bulbs drawing various wattages;

'In the-event thatthe first light bulb. 22 burnsout, the t coil of the double pole double throw relay, 21 becomes deenergized since itscircuit will. beinterrupted at the brolgen filarnent ofthe light bulb. 22. lnpthein inactivated or normal state, the armatures 36 andliicof the doublepoledoublethrow relay 21, respectively c'onaplete 7 the circuit of the second light bulb 31and direct thercoil.

cireuit of-thesingle pole -single throw relay 2% through the-filament-offthesecondbulb 31. Current is then fed to the second bulb'3l' through a resistor 32 quantitatively seleeted to maintain a suitable: current balance between the" coil-*ofthe 'single pole-single throw relay Zlland the. second-bulb -31. While the: electrical values of the resisters 23* and 32 difier,'their functions are alike; the

resistors-24 and'33'likewise have diiferent electrical v alues but serve identical-functions fortheii're'sbecti'yebulbs. Asthe second bulb 31 burns, the armature 39 or" .tlte-single 'pole single throw relay--20 remains in its actua'ted position and interrupts the circuit of" the battery operated current fails, the coil circuits of both relays 2t and will be interrupted and the armatures thereof will assume theirnormal positions. With the single'pc-lesingle throw relay ZG d'eenergized, the normal position'of itstarmature. completes the battery current circuit o f the third light 41' ands-emergency illumination is thereby provided.

'The wiring of' the double pole double throwswitch A is such that its armatures 12 and 43 serve asconductors of line and battery current respectively. The upper contact points 46 and 13 connect these current sources with a clock operated switch 15 while the lower contact points 4Z1a'nd 47' serve to. bypass the clock. operated switch.

In the-event that both the first and sec- 0nd bulbs 22 and 31 burnout or that the source-'ofline Thus,.the.. double pole double throw switch A may be used to operate the lights directly, to operate the lights nected to the master unit of the invention or for the operation of subordinate. units. A battery poweredtico ntrol current outlet 52 and Ellis provided for the emergency control of subordinate units. a p p 7 7 The construction and circuitry of a subordinate unit (a illustrated in Figure 2) is, in many respects, identical with the construction and circuitry of the described inasr ter unit. Those skilled in theart will readily; recognize the similarities and will see upon comparison of the two units that the principal diiferences reside inthe absence; of the mainswitches and placement of 'a second single pole single throw relay in the circuitof the battery open ated light.

like numbers in the two figures and are suifixed by the letter a in the diagram of the subordinate unit. r

I In the drawing with particular reference tothe' sub ordinate unit (Figure 2), line currentsourcexwiresallaj and 270 are electrically connected to power. line outlets: 50 and 49 of the master unit. Lights 22a andjfila; are

wired to the line current source through identical com-L ponents and in like manner to the lights 22and31zofzthe;

master unit. Control current inlet lines 54 andTSS are.

electrically connected to, the control currentoutletlines 52 and 53' of the master unit.

terminal of the actuating coil of the second 'sin gle pole single throw relay .56: is wired to the: armature 39a of'the'fir'st single pole single throw relay 20a. The .nor'mally closed contact point 40a ofthe first single polesingle throw relay 20a is Wired to the other controlcurrent'inletgwire 55. One terminal of-a battery 38ais' wired to the arma ture' 57 of the second single pole single throw relay 56'. The normally opencontact point 58 ofthe seeond" single pole single throw relay 56 is electri'cally'connec'ted to a terminal of the third bulb 41a. The 'second' terminal of the third bulb 41a is Wired to the second terminal of the battery 380. A switch 59 is provided in one of the. line current inlet wires.

In operation of the. subordinate unit, the first and'sec- 0nd bulbs 22a and 31a are operated by therelays as in the master unit.

and 31a of the subordinate unit burn -out. ln the aba sence of linecurrent,.or with the. switch A'of thejmaster unit in open position, or withswitch Ac'l'osecl in the up per position and the clock operated switch 15jin open position, the third bulb 41 ofthe master.-

and the third bulb Ala .of the subordinate. unit may ,be gillu minated by closing the battery testpushfbutton 48"of'the master unit,

,The invention is notlimited top'the exemplary construction herein shown andflescribed; but'maybe madej; 1n:various ways within the scope of the appended claims:

in order to avoid repetitious description identical components with identical functions are given One control 'current inlet line 54 is: wired .to a terminal of the actuating oil t of a second single pole single throw relay 56: The other In the second single pole single throw" relay 56, however, the dependence upon actuating cur rent from thermaster unit prevents actuation of the-third bulb 41a when the masterunit is not turned on. The third bulb 41a is activated if the master unit-is: switched on and a power tailureoccursorthe first two bulbs'22d- What is claimed is:

l. A night light comprising a source of electrical current, an electric light bulb wired to said source of electrical current, a double pole double throw relay having its actuating coil wired in series with said electric light bulb, an electrical resistor wired in series with said electric light bulb and in parallel with the actuating coil of said relay, a second electric light bulb wired in parallel with the first said electric light bulb through an armature of said relay and the contact thereof, a second resistor wired in series with the second said electric light bulb, a second relay having its actuating coil wired in parallel with the first said resistor and in series with the first said electric light bulb through a second armature of the first said relay and a cold open contact point of the second said armature of the first said relay and wired in parallel with the second said resistor and in series with the second said electric light bulb through the second said armature of the first said relay and through the cold closed contact point of the second said armature, a battery and a third electric light bulb wired to said battery through the armature of the second said relay and through the cold closed contact point of the said armature of said second relay.

2. The invention as defined in claim 1 and wherein a third resistor and a manual switch are wired in series with one another and in parallel with the first said resistor and in series with the first said bulb, and a fourth resistor and a second manual switch wired in series with each other and in parallel with the second said resistor and in series with the second said bulb.

3. The invention as defined in claim 1 including a clock operated switch and alternative means to connect said source of electrical current and said battery to the said lights respectively associated therewith either directly or through said clock operated switch.

4. The invention as defined in claim 3 including a subordinate unit including a first plug wired to said source of electrical current in series through said clock operated switch and said alternative means, and directly through said alternative means; a second plug wired to said battery in series through said clock operated switch and said alternative means, and directly through said alternative means, a fourth electric light bulb Wired to the first said plug, a third relay having its actuating coil wired in series with the fourth said electric light bulb, a fifth electrical resistor wired to the first said plug in series with the fourth said electric light bulb and Wired in parallel with the actuating coil of the third said relay, a fifth electric light bulb wired in parallel with the fourth said electric light bulb through an armature of the third said relay and through a cold closed contact point of said armature of the third said relay, a sixth electrical resistor wired in series with said fifth electric light bulb, a fourth relay having its actuating coil wired in parallel with the fifth said resistor and in series with the fourth said electric light bulb through a second armature of the third said relay and a cold open contact point of the second said armature of the third said relay and wired in parallel with the sixth said resistor and in series With the fifth said electric light bulb through said second armature of the third said relay and the cold closed contact point of said second armature of the third said relay, a second battery, a fifth relay having its actuating coil wired to the second said plug through the armature of the fourth said relay and through the cold closed contact point of the armature of the fourth said relay, and a sixth electric light bulb wired to the second said battery through the armature of the fifth said relay and through the cold open contact point of the armature of the fifth said relay.

References Cited in the file of this patent UNITED STATES PATENTS 

